DIY: Reset Airbag Computer Crash Data




Introduction: DIY: Reset Airbag Computer Crash Data

When a vehicle is rebuilt after a collision involving airbag
deployment, the airbag computer must be replaced. Here’s a video on how to clear the crash data from the airbag computer and reprogram it with clean virgin data.

Step 1: Introduction

The airbag computer controls the supplemental restraint
system in your vehicle, including the airbag sensors, inflators and seat belt pretensioners. It also acts as a black box when you get into a major collision that involved airbag deployment.

Let’s say you get into a collision with your beige Corolla.

And your airbags deploy:

Step 2: Airbag Computer's Cannot Be Reused

Well if you decide to rebuild the vehicle and replace the airbags:

You need to replace the SRS computer, since it has a hard
code inside that can’t be erased and you’ll be stuck with an airbag light on:

You won’t even be able to access the SRS computer using
Toyota’s techstream software either:

Step 3: Remove the Airbag Computer

The airbag computer is located underneath the dashboard. The
bottom half needs to be removed to access it.

battery before working on SRS system:

Step 4: Disasemble the Airbag Computer

Airbag computer removed:

Open up the computer:

We’re looking for this 8 pin SMD EEPROM chip here that stores the crash data, it says L56R on it:

Step 5: Solder and Hookup to an EEPROM Reader

Solder some 32 gauge hookup wire to connect it to the serial
port EEPROM reader:

I built a little EEPROM reader using some resistors and diodes:

Here’s the setup, with the airbag computer EEPROM going to
the reader, and then the reader going to the serial port directly on a legacy Pentium 4 computer. You can also purchase USB EEPROM readers:

Step 6: Analyze Crash Data

Then I used PonyProg software which is a serial device
programmer to read from the EEPROM chip:

Here’s what the crash data looks like:

From a clean, uncrashed Corolla, I dumped the information
from its SRS computer and it looks like this:

Comparing the two, you can see a lot of data values have

So now I’m going to replace all the values from the crashed chip with those from the virgin chip and rewrite it to the computer to clear the hard code. Then I’ll replace it into the vehicle:

Step 7: Replace the Airbag Computer

So now I’m going to replace all the values from the crashed chip with those from the virgin chip and rewrite it to the computer to clear the hard code. Then I’ll replace it into the vehicle:

Step 8: Test to Make Sure It Works

The SRS light should go out within 6 seconds if everything
is functioning normally. I also double checked it with Toyota’s techstream software and there aren’t any codes or faults found.

And It works!

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    Question 2 years ago on Step 4

    How do you know SMD EEPROM stored all the crash data?


    2 years ago

    if you do not have the vehicle specific test tools you can use a low watt resister of same value of the air bags, seat belts. I think Ford uses a 47ohm resister. Plug a resistor in to every connector for each air bag and seat belt and if it is reset correctly the dash airbag light should go out and have no codes. If not reset properly and the module wants to deploy an airbag or belt the resistor will fail.


    3 years ago

    Hi, Thank you for this video. DO you have any idea about resetting an Airbag module when crash data is in an EEPROM which is inside a micro controller? I mean when there is no 8pin EEPROM on the board? Like Airbag sensor Toyota, 89170 - 06720 (53)


    Question 3 years ago on Introduction

    must you change values of reading or can you write the virgin file to crash module as is ?


    4 years ago

    you could have it a bit easier, you could use a Programmer Clip like this.


    4 years ago

    Hi Again, Have you ever disabled the immobilizer? Im asking because I can buy a car with an with an immobilizer fault or lost keys for very cheap, and you can buy an new ECU with the immobilizer disabled, but I really like the idea of doing it myself.

    Screen Shot 2017-11-22 at 7.52.11 pm.png

    5 years ago

    Thanks that is good info. The duck was a nice touch. :-0

    How long did it take you to find out it was that eprom that was the problem?


    Reply 5 years ago

    Thanks! You made it to the end of the video haha.

    I did some research and found that there are services out there that clear the info from the SRS computer. I have previous experience working with EEPROM's so as soon as I opened up that motherboard I knew where to head.